Sound stabilizer



April 9, 1940- w. E. MERRIMAN SOUND STABILIZER filed oat. 1s, 193e l NVEN T0152 h////amEMe/-r/mn www j AToRA/EYS Patented Apr. 9, 194i) l IUNITED STATES PATENT OFFICE SOUND STABILIZER William E. Merriman,Rochester, N. Y., assigner to Eastman Kodak Company. Rochester, N. Y., acorporation of New Jersey Application October 13, 1938, Serial No.234,809

' '12 claim.. (cl. lis-16.2)

The present invention relates to a sound cam- Still another object ofthe invention is the era of the'lm magazine type in which a lm aprovision of a stabilizer of the class described strip is intermittentlypassed in front of a picwhich is inexpensive to manufacture, simple inture exposing aperture, and is then continuously construction, automaticin its operation, and l passed in front of a sound exposing aperturehighly desirable in its results. 5 which is spaced a definite distancefrom the To these and other ends, the invention resides pictureaperture. in certain improvements and combinations of In order to securea true reproduction on the parts all as will be hereinafter more fullydefllm strip of the sound being recorded, it is highly scribed, thenovel features being pointed out in essential that the film strip bemoved at a subthe claims at the end of the specification. l0

stantially constant and uniform lineal speed past In the drawing: thesound recording aperture, and that the sound Fig. 1 is a side view of asound camera of the drum be spaced the proper distance from the filmmagazine type with the side plate of the objective lens of the soundoptical system. As camera and the magazine cover removed, and

lli is well known, it is difficult and highly expensive with a portionof the magazine in section, showto manufacture parts which areabsolutely free ing the mechanisml for moving the film strip from slightimperfections and/or eccentricities. through the magazine, and thelrelationthereto These imperfections .and eccentricities in the of arotary stabilizer constructed in laccordance various film drivingmembers together with any with the preferred embodiment of theinvention.

slight imperfection in the film strip itself may Fig. 2 is a fragmentarysectional view of a 20 cause small momentary variations orfiuctuaportion of the camera and magazine illustrated tions in thelineal speed of the film strip as the in Fig. 1, but on a larger scalethan the latter', latter passes the sound aperture. Such variashowingonemethod of operatively connecting tions, if not corrected, willobviously distort the the rotary stabilizer to the sound recording drumsound record, the disadvantages of which are obfor maintaining a uniformfilm Speed et the 26 vious to those in the art, In addition, in orderSound aperture; and for retaining the sound to accurately record thehigher sound frequendrum the proper distance from the objective lenscies on the film strip,A the sound drum must not of the sound opticalsystem. only be spaced the proper distance from the Fig. 3 is a Viewsimilar to Fig. 2, showing a objective lens of the sound system, butthis dismOded arrengement fOr Connecting the Ste- 80 tance must beaccurately maintained, irrespecbilizer to the sound drum. tive of theposition of the magazine in the cam- Fig. 4 is a view similar to Figs. 2and 3 showing era.; One object of the invention is the provision a stillfurther modification of connecting or of a device for damping orfiltering out any clutching the stabilizer to the sound drum; and

small momentary variations in the lineal speed Fig. 5 is an end view ofa portion of the mecha- 35 of the film strip to insure that the latterwill be nism illustrated in Fig. 3 showing the arrangefed at a uniformrate past the sound aperture. ment by which the opening in the filmmagazine Another object of the invention is the proviis closed to affordthe necessary light lock theresion of a support for the sound drum whichwill for.

not only support the latter .in registry with the Similar referencenumerals `throughout the 40 sound aperture, but will also maintain thefilm Various VOWS indicate the Same DaTtS strip on the sound drum theproper distance from Fis. 1 of the drawing Shows a sound camera thesound objective lens. formed with a case or housing I i on the front ofA further object of the invention is the proviwhich the camera orpicture objective lens I2 sion of a rotary stabilizer whichautomatically is mounted. .A film magazine7 generally ind- 45 adjustsitself to compensate for minor variations cated by the numeral I3y iSPleeeeble Within the in the feeding mechanism so as to insure aunivcamera housing end eentains e Supply 0f lln form film speed at thepoint of sound recording. which is intermittently fed past apicture-expos- Yet another object of the invention is the proinsaperture t0 reeOl'd the Picture, and S then 5o vision of such astabilizer which can be attached continuously fed pest e Sound aperturet0 record 50 to existing cameras of the sound magazine type. the soundimage on the marginal edge of the A further object of the invention isthe provifilm, all as will be hereinafter more fully exsion of astabilizer which is automatic in its plained. A definite length'of filmis maintained operation and thus requires no attention on the betweenthe picture and sound apertures so as part of the operator. to maintainthe proper synchronism between 55 the picture taking and the soundrecording, as is well known in the art.

The film magazine i3 contains a supply roll i4 of unexposed film. Thefilm strip F is drawn from the roll i4 by a constantly driven sprocketi5, the teeth i6 of which engage the marginal perforations in the filmstrip to feed the latter to the upper supply lm loop I1 and the filmgate i8. A suitable pull-down mechanism I9 intermittently pulls or feedsthe film strip through the gate I8 and past the picture-exposingaperture 20 where the nlm strip is exposed to the image formed by thepicture objective lens i2. The strip F then passes downwardly to thelower film loopI 2i formed by a spring 22 of the shape best shown inFig. l. This spring is so shaped as to also'hold the moving film stripagainst a pair of rollers 23 positioned below the sprocket l5, asclearly shown in Fig. l.

The strip F is then looped over a sound drum 26, to be later more fullydescribed, and then under a guide roller 21 and finally between thesprocket l5 and the rollers 23 to the takeup roll 28, all as clearlyshown in Fig. 1. As the strip F passes around the drum 26 a marginaledge of the strip passes across a sound aperture 29 for recording thesound image on the film strip. It is apparent from an inspection of Fig.i, that as the sprocket I5 is driven the film strip F will be drawn overthe drum 26 to rotate the latter, and to `continuously feed the strip Fpast the sound aperture 29, the drums being arranged in a loop 33 of thestrip F. The pulldown mechanism i9 on the other hand, intermittentlyfeeds the strip F through the film gate i6 and past the picture aperture20. The mechanism for driving the sprocket I5 and the pull-down i9 arepositioned in a mechanism chamber 30 formed by the spaced walls 3l and32 on the sides of the camera housing Il. An outer wall 45 of the camerahousing is spaced from and secured to the wall 32 in any suitable andwell-known manner.

In recording the sound, the image of a lamp filament 34 passes through acondensing lens 35 and is imaged on a galvanometer mirror 36 which isconnected to the sound pick-up mechanism, not shown. The image on thegalvanometer mirror 36 is reflected onto a light slit 31 formed in aplate 38. The portion of the sound image which passes through the slit31 is reflected by means of a prism 39 and a sound objective lens 40through the sound aperture 29 and onto the film strip F, all as wellknown to those ln the art.

The above-described mechanisms, with the exeeption of the sound drum 26,may be of any suitable and we1l-known construction and do not constitutea part of the present invention.

It is well known in the art, thataccurate and true reproduction of thesound can only be secured when the film strip is fed at a constant anduniform lineal speed past the sound aperture 29, and when the lm strip,during its passage past the sound aperture, is maintained the properdistance from the sound objective lens 40. It is also well known, forthe reasons pointed out above, that it is quite difficult, if notimpossible, to provide an absolutely smooth uniform motion to theVarious feed mechanisms. Any slight momentary variations in the variousfeed ing mechanisms will tend to correspondingly vary the speed of thesound drum 26, and hence the speed of the film strip F past the soundaperture 29, thus .distorting the sound image, the disadvantages ofwhich are obvious to those in the art.

In order to overcome these disadvantages, the

present invention provides a rotary stabilizer, or viscous flywheel,generally indicated by the numeral 42. This stabilizer is mounted in themechanism chamber 30 and is operatively connected to and driven by tilesound drum 26, in a manner to be presently described. This stabilizer isarranged to automatically and mechanically dampen or filter out anyslight momentary variations in the speed of the drum 26, thus insuring asmooth and substantially uniform speed of the film strip past the soundaperture 29. In addition the supporting means for the stabilizer engagesthe drum vto support the latter substantially in registry with the soundaperture, as well as retaining the drum the r )per distance from thelens 4U. By means of suon an arrangement a true, accurate recording ofthe sound is assured.

The stabilizer 42 is mounted on and supported by a shaft 43 which isslidable axially in bearings 44 in the chamber 30. This stabilizer, inthe present embodiment, is in the form of a viscous fly-wheel andcomprises an outer cylindrical member 46 formed with a hub 46a rigidlysecured to and movable as a unit with a shaft 43, and a secondarycylindrical member 41 positioned within the outer member 46 and looselymounted on a shaft 43, as clearly shown in Fig. 2. The space 48 betweenthe members 46 and 41 is filled with a fluid 49, such as oil, whichaffords the sole driving connection between the two members 46 and 41.Suitable seals 52 are provided between the shaft 43 and the outer member46. As the stabilizers 42 in Figs. 2, 3, and 4 are identical inconstruction the detailed showing thereof is made only in Fig. 2, theremaining figures merely showing the outside view of the completestabilizer.

It is apparent from inspection of Fig. 2 that when the shaft 43 isrotated, the outer member 46 will also rotate as a unit therewith. When,however, the member 46 is thus rotated, the inner surfaces 66 thereofwill frictionally engage the oil 49 and will provide, in effect, aslipping friction clutch between the member 46 and the oil 46 togradually bring the latter, as a unit, up to the speed of the member 46.4The rotating body of oil 49 will, in turn, frictionally engage theouter surface 5l of the inner member 41 to drive the latter. Finally theinner and outer members will rotate, as a unit, at the-same angularspeed.

However, should the speed of the shaft 43 momentarily increase, thespeed of the outer member 46 will correspondingly increase. The innermember 41 and the oil 49, due to their inertia, will however tend torotate at the same speed and will thus act as a brake on the outermember 46 to return the latter and the shaft 43 to their previousspeeds. If, on the other hand, the shaft 43 tends to momentarilydecrease in speed, the outer member 46 will thus tend to run slower thanthe inner member 41 and the oil 46. These latter members will then actas a driving member vand will tend to bring the outer member 46 up tothe speed of the inner member 41. Thus the inertia of the rotatingmember 41 and the body of oil 49 will tend to maintain the speed of theouter member 46, and hence the shaft 4I, substantially constant anduniform. It is apparent, therefore, that such a stabilizer willenectively dampen or filter out any slight momentary variations in thespeed of the shaft 44 and thus hold the speed of the lattersubstantially constant and uniform.

the filmstrip F will be fed past the sound aperture 29 at a uniform rateto provide an accurate recording of the sound image, the advantages ofwhich are obvious to those in the art. In addition, the shaft 43 willsupport the drum 26 and will thus bring the horizontal axis thereofsubstantially in alignment with the sound aperture 29. But what is moreimportant. the shaft 43 will accurately maintain the film strip- F as itpasses the aperture 29, the proper distance from the lens 40irrespective of the position of the wall 53 of the magazine I3. In thevarious modications, the shaft 43 and the stabilizer 42 are permanentlymounted in the camera housing, and are automatically coupled or clutchedto the sound drum 26 on placing or positioning the magazine I3 withinthe camera housing.

In the embodiment illustrated in Fig. 2, the left end of the shaft 43extends through the wall 3| of the mechanism chamber 33 and throughregistering opening 55 formed in the side 55 of the magazine I3. Theshaft is formed with a tapered portion 51 which is arranged to engage acorrespondingly tapered periphery 58 of a central opening 59 of the drum25. This engagement of the portion 51 with the periphery 58 forms, ineiect,.a friction clutch which affords a driving connection between thedrum 25 and the shaft 43, as is apparent from an inspection of thisfigure.

A leaf spring 66 has one end 5I thereof secured to the wall 32 while alug or protuberance 52 on the free end thereof engages the right end 53of the shaft 43 to urge the latter to the left, as viewed in Fig. 2, tomaintain the portion 51 and the periphery 58 in frictional contact. Thusthe drum 25 is held in driving engagement with the shaft 43, and thelatter serves, to support the drum so that the horizontal axis thereofwill be maintained in registry with the sound aperture 29 and the filmpositioned the proper distance from the sound objective-lens 43. Aprotuberance or lug 64 formed on the cover 55 of the magazine I3 engagesthe left face 56 of the drum 26 and cooperates with the shaft 43 tosupport the drum. Inorder to prevent fogging of the film strip F, asuitable light lock must necessarily be provided for the opening 55.

' In the embodiment shown in Fig. 2, such a light lock is provided byforming an annular flange or collar 61 around the opening 56. Thisflange is arranged to extend into a registering annular recess 55 formedin the drum 26, as clearly shown in Fig. 2.

By means of this arrangement, the shaft 43 and the stabilizer 42areoperatively connected to and driven by the drum 26. Therefore, anyslight momentary variations in the speed of the drum 25, for the reasonspointed out above, will be immediately dampened or ltered out by thestabilizer 42 thus insuring a smooth uniform speed of the drum 25. Inaddition, the film strip will be accurately positioned relative tothelens 43. With the speed and position of the film strip thus preciselymaintained, the strip will accurately record the sound image whichpasses through the slit 31.

vfull length and extends into When the magazine I3 is not in the camerahousing Il, the spring 55 slides the shaft 43 leftwardly in the bearings44, as viewed in Fig. 2, until the hub 46a engages the left-hand bearing44 to limit further leftward movement of the shaft 43. I'he shaftremains in this shifted position as long as the housing II containsnomagazine I3. However, when the magazine is placed in the vcamerahousing, the opening 59 of the drum 25 shaft 43. The

25 and a shaft 43.

A modified driving connection between the drum 26 and the shaft 43 isshown in Fig. 3. Parts in this modification which correspond to thoseink Fig. 2 are designated by the same numerals and need not be furtherdescribed. In this modification. the shaft 43 is the same diameter forits a cylindrical opening formed in the drum 25. The opening 15 may beof such a size as to slidably receive the the shaft 43 toprovide aslight driving connection therewith. It is preferred, however, toprovide an additional means in the form of a friction clutch, generallyindicated by the numeralk 14, for operatively connecting the drum 26 indriving engagement with the shaft 43.

To secure this result, the drum is formed with a reduced portion orcollar 15 which ex tends through an opening 11 in the side wall 18 ofthe magazine I3. The outer end of the coilar15 is formed to provide aradially extending disk 19 which registers with a similar disk 80rigidly secured to the shaft 43. One or both of the disks 19 and 86 areprovided with a facingA II of cork or other suitable material to providea friction clutch drive between the two disks 19 and 50 so that thestabilizer 42,may be operatively connected to the drum 26 to control thespeed of the latter. In order to provide suitable space for the frictionclutch 14, the wall 3I of the chamber 30 and the adjacent sides 18 ofthe magazine I3 are bent out as shown in Fig. 3.

In order to assemble the drum 26 in the maga'- zine I3, the opening 11inthe side 18 must be slightly larger than the drum to permit the latterto be passed therethrough and into the is brought into registry with themagazine is now slid into posi- 5 non tobnng the periphery sa of theopening sa f magazine, as is apparent from an inspection of y Fig. 3.This large opening is closed, in the present embodiment, by means of apair of oppositely arranged U-shaped members 82, of the shape best shownin Fig. 5. These members are slid towards each other from opposite sidesof the collar 15 so that the curved portions 83 thereof engage thecollar, while the members themselves are arranged in overlappingrelation, as shown in Fig. 3, to effectively cover the opening 11 toprovide a light lock therefor.

A leaf spring 84 has one end 85 thereof secured to the outer surface 86of the side 32 while the intermediate portion is formed with a lug orprotuberance 81 which engages the end 88 of the shaft 43 to move thelatter to the left, as viewed in Fig. 3, to yieldably maintain themembers of the friction clutch 14 in driving engagement. A Z-shaped lug89 is secured to the surface 85 of the wall 32 and is arranged in thepath of the free end 95 of the spring 84 to limit the rightward movementthereof, as viewed in Fig. 3,

when a magazine is placed in the housing, in the manner described inconnection with Fig. 2.

The embodiment in Fig. 3, thus affords a friction clutch whichoperatively connects the stabilizer 42 in driving engagement with thesound drum 26 so as to filter out any slight variations in the speed ofthe drum. The shaft 43 also cooperates with the protuberance 64 on themagazine cover 65 to support the drum 25 in proper position relative tothe sound aperture 29 and the lens 40.

Fig. 4 shows still another arrangement for forming a driving connectionbetween the stabilizer 42 and the sound drum. The parts corresponding tothose in the other figures will be designated by the same numerals. Asthe sound drum in this embodiment is of a slightly different shape thanthose described, it will be designated by the numeral 26a. This drum isformed with a large central opening 94 in which is press fitted a sleeveor bushing 95. The right hand end of the opening 94 is countersunk toprovide an annular recess 96 arranged to receive the annular flange 6ito provide a light lock for the opening 55 in the side 56 of themagazine, as described in connection with Fig. 2 above.

The right end of the bushing 95 is formed with an annular rib or flange9`| the face of which is formed with a row of axially extending teethwhich are arranged to engage with a corresponding row of teeth 99 whichproject axially from a fiange |00 formed on the left end of the shaft43, Fig. 4. Thus when a magazine is in position in the camera housing,the teeth 98 and 99 engage to provide a positive driving connectionbetween the stabilizer 42 and its shaft 43 and a sound drum 26al Theleft end of the bushing is formed with a countersunk recess |0| in whichis positioned a ball |02. This bali engages a fiat spring washer |03secured to the inner surface |04 of the magazine cover 65 to yieldablyurge the sound drum 26a, with its bushing 95, to the right, as viewed inFig. 5. 'I'he right end of the shaft 43 is supported in a ball thrustbearing |05 which is mounted in the wall 32, as shown. The drum 26a isthus resiiiently moved toward the shaft 43 to bring the teeth 98 and 99into engaging relation to positively connect or clutch the drum to theshaft 43 and the stabilizer 42 so that the latter may control the speedof the film strip past the sound aperture, as above described. As thebushing 95 is tightly fitted within the drum 29a it, in effect, is apart thereof so that the teeth 98 may be broadly considered as formed onthe sound drum.

In all of the above arrangements, the sound drum is suitably clutched tothe shaft which carries the stabilizer so that the latter is operativelyconnected to the drum. By means of such a connection, the stabilizer iseffective to quickly and automatically dampen out any slight momentaryspeed variations in the sound drum, which variations may result fromslight imperfections in the film strip, or imperfections oreccentricities in the various driving members. Thus a smooth uniformsound drum speed is insured. In addition, the stabilizer shaftaccurately positions the film strip relative to the sound objectivelens. thus assuring true sound recording, the advantages of which areobvious.

While certain embodiments of the invention have been disclosed, it is tobe understood that the inventive idea may be carried out in a num ber ofways, This application is therefore not' to be limited to the precisedetails described, but is intended to cover all variations andmodifications thereof falling within the spirit of the invention or thescope of the appended claims.

I claim:

l. In a motion picture camera, the combination with a film magazineplaceable within said camera, means for moving a film strip through saidmagazine and past exposure and sound apertures formed therein, a sounddrum positioned within s aid magazine adjacent said sound aperture andarranged in a loop of said strip to be driven solely thereby, of meanson said camera directly engaging said drum and cooperating with saidmagazine for supporting said drum in alignment with said sound aperture,and a mechanical filter on said supporting means and actuated solely bythe movement of said film strip over said drum for maintaining a uniformfilm speed at said sound aperture.

2. In.a motion picture camera, the combination with a film magazineplaceable within said camera, means for moving a film strip through saidmagazine and past exposure and sound apertures formed therein, a sounddrum positioned within said magazine adjacent said sound aperture andarranged in a loop of said strip to be driven thereby, of meansincluding a shaft mounted on said camera and engaging said drum tosupport the latter in registry with said sound aperture, means formaintaining said shaft in engagement with said drum, and means on saidshaft for filtering out any speed variations of said drum.

3. In a motion picture camera, the combination with a film magazineplaceable within said camera, means for moving a film strip through saidmagazine and past exposure and sound apertures formed therein, a sounddrum positioned within said magazine adjacent said sound aperture andarranged in a loop of said film, a sound lens adjacent said soundaperture, of means including a shaft slidably mounted on said camera andarranged to engage said drum to support said drum in registry with saidsound aperture and to maintain said drum at a fixed distance from saidlens, and means for yieldably maintaining said shaft in engagement withsaid drum.

4. In a motion picture camera, the combination' with a film magazineplaceable within said camera, means for moving a film strip through saidmagazine and past exposure and sound apertures formed therein, a sounddrum positioned within said magazine adjacent said sound aperture andarranged in a loop of said film so as to be driven solely thereby, asound lens adjacent said sound aperture, of means on said cameradetachably engaging said drum for supporting the latter in registry withsaid sound aperture, means on said supporting means and actuated solely`by the movement of the film strip over said drum for maintaining auniform film speed at said sound aperture, means releasably engagingsaid drum to retain the film strip thereon a fixed distance from saidlens, and means for yieldably retaining said drum engaging means inoperative relation with said drum.

5. In a motion picture camera, the combination with a film magazineplaceable within said camera, means for moving a film strip through saidmagazine and past exposure and sound apertures formed therein, a sounddrum positioned within said magazine adjacent said sound aperture andarranged in a loop of said strip to be driven thereby, of means on saidmagazine for supporting one end of said drum, means on said cameraarrangedkto frictionally engage a central opening in said drum andcooperating with said supporting means for maintaining said drum inregistration with said sound aperture, and a flywheel on said drumengaging means and driven solely by the movement of the film strip oversaid drum for maintaining said drum at a uniform speed,

6. In a motion picture camera, the combination with a film magazineplaceable within said camera, means for moving a film strip through saidmagazine and past exposure and lsound apertures formed therein, a sounddrum positioned within said magazine adjacent said sound aperture andarranged in a loop of said strip to be driven thereby, of means on saidmagazine for supporting one end of said drum, an axially movable shaftmounted on said camera, said shaft having a portion thereof extendinginto and engagingsaid drum and cooperating with said last mentionedmeans for maintaining said drum in registry with said sound aperture,resilient means for moving said shaft axially to maintain said portionin engagement with said drum, and a mechanical filter on said shaft formaintaining a uniform drum and film speed at said sound aperture.

7. In a motion picture camera, the combination with a nlm magazineplaceable within said camera, means for moving a film strip through saidmagazine and past exposure and sound apertures formed therein, a sounddrum positioned within said magazine adjacent said sound aper-r ture andarranged in a loop of said strip to be driven thereby, a sound lensadjacent said sound aperture, of means on said magazine for supportingone end of said drum at the axis thereof, av shaft slidably mounted onsaid camera in alignment with said drum axis, said shaft having aportion thereof arranged to extend through said magazine and into anaxially formed opening in said drum, means for operatively connectingsaid drum to said shaft, said connecting means cooperating with saidsupporting means for maintaining an axis of said drum in registry withsaid sound aperture and for retaining said drum a xed distance from saidlens, a leaf spring mounted on said camera and engaging said shaft tomove the latter axially to engage said connecting means, and a flywheelcarried by said shaft for assuring a uniform speed of said film strip asthe latter passes said sound aperture.

8. In a motion picture camera, the combination with a, film magazineplaceable within said camera, means for moving a film strip through saidmagazine and past exposure and sound apertures formed therein. a sounddrum' positioned within said magazine adjacent said sound aperture andarranged in a loop of said strip to be driven thereby, of means on saidmagazine for supporting one end of said drum at the axis thereof, ashaft slidably mounted on said camerain alignment with said drum axis,said shaft having a portion thereof arranged to extend through saidmagazine and into an axially formed opening in said drum, means foroperatively connecting said drum to said shaft, said connecting meanscooperating with said supporting means for maintaining thefaxis of saiddrum in registry with said sound aperture, a leaf spring mounted on saidcamera and engaging said shaft to move the latter axially to engage saidconnecting means, cooperating means on said magazine and said drum foraffording a light lock adjacent said shaft, and a viscous flywheelcarried by said shaft for maintaining a uniform speed oi' said filmstrip as the latter passes said sound aperture.

9. In a motion picture camera, the combination with a film magazineplaceable within said camera, means for moving a film strip through saidmagazine andr past exposure and sound apertures formed therein, a sounddrum positioned within said magazine adjacent said sound aperture andarranged in a loop of said strip to be driven thereby, of a shaftrotatably and slidably mounted in said camera, said drum being formedwith an axiallyv extending opening, a portion `of said shaft extendingthrough an aperture formed in said magazine and into said opening andengaging the periphery thereof to support said drum and to maintain theaxis thereof in registry with said sound aperture, means forfrictionally connecting said drum to saidvshaft so that the latter maybe driven upon rotation of said drum, means for maintaining saidfriction connecting means in engagement, and a flywheel on said shaftfor maintaining a uniform film speed as the film strip passes said soundaperture.

10. In a motion picture camera, the combination with a film magazineplaceable within said camera, means for moving a film strip through saidmagazine and past exposure and sound apertures formed therein, a sounddrum positioned Within said magazine adjacent said sound aperture andarranged in a loop of said strip to be driven thereby, of means on saidmagazine for supporting one end of said drum at the axis thereof, ashaft rotatably and slidably mounted on said camera and in alignmentwith said drum supporting means, said drum being formed with.

an axially extending tapered' opening in alignment with said shaft, atapered portion on said shaft arranged to extend into said opening andto engage the periphery thereof to frictionaily connect said drum tosaid shaft to drive the iatter from said drum, a leaf spring mounted onsaid camera and engaging said shaft to move the latter axially tomaintain said portion in frictional engagement with said periphery, anannular rim in said magazine concentric Withsaid shaft and extendinginto a cooperating annular recess formed in said drum to afford a lightlock for said magazine, .and a'flywheel carried byv said shaft formaintaining a uniform speed on said film strip as the latter passes saidsound aperturel l1. In a motion picture camera, the combination with afilm magazine placeable within said camera, means for moving a filmstrip through said magazine and past exposure and sound apertures formedtherein, a sound drum positioned lwithin said magazine adjacent saidsound aperture and arranged in a loop of said strip to be driventhereby, of means on said magazine for supporting one end of said drumat the axis thereof, a collar on the other end of said drum extendingthrough an aperture in said magazine, said collar and drumbeing formedwith an axially extending opening in alignment with said drum supportingmeans, a shaft rotatably and slidably mounted on said camera, a portionof said shaft arranged to extend into said opening and cooperating withsaid supporting means `to support said drum to maintain the axis thereofin registry with said sound aperture. friction clutch members carried bysaid shaft and said collar for operatively connecting said shaft to saiddrum, a leaf spring in said camera engaging said shaft to hold saidclutch members in driving engagement so that said shaft may be driven bysaid drum, a pair of U-shaped discs arranged in overlapping relationover said aperture to afford a light lock therefor, and a flywheel onsaid shaft for controlling the speed of said drum to maintain said fllrnstrip at a constant speed as it passes said sound aperture.

12. In a motion picture camera, the combination with a lrn magazineplaceable within said camera, means for moving a film strip through saidmagazine and past exposure and sound apertures formed therein, a sounddrum positioned within said magazine adjacent said sound aperture andarranged in a loop of said strip to be driven thereby, of a flat springmounted on said housing, said druml being formed with an axially openingextending therethrough, a ball positioned in one end of said opening andengaging said spring to provide a point support for one end of saiddrum, said drum being formed with an annular recess adjacent andconcentric with said opening, an annular flange on said magazineextending into said recess to afford a light lock, an annular row ofteeth formed on the other end of said drum, a shaft rotatably andslidahly mounted in said camera, an annular row of teeth formed on oneend of said shaft and arranged to cooperate with the teeth on said drumto clutch the latter to said shaft so that said drum may drive saidshaft, and a flywheel carried by said shaft for automaticallycontrolling the speed of said drum to insure a uniform film speed as thelatter passes said sound aperture.

WILLIAM E. MERRIMAN.

